Airplane propulsion means



March 5, 1940. c. GREEN 2,192,469

AIRPLANE PROPULSION MEANS F iled June 9, 1939 2 Sheets-Sheet 1 Inventor March 5, 1940. i 'C GREEN 2,192,469

AIRPLANE PROPULSION MEANS Filed June 9, 1939 2 Sheets-Sheet 2 In ventor Larlflrwn.

A itorneys Patented Mar. 5, 1940 UNITED STATES AIRPLANE PROPULSION MEANS Carl Green, Ever-sole, Ky., assignor of one-half to Tilmon J. Green, Eversole, Ky.

Application June 9, 1939, Serial No. 278,367

1 Claim.

The present invention relates to new and useful improvements in airplane propulsion means and has for its primary object to provide, in a manner as hereinafter set forth, an apparatus of this character comprising a pair of oppositely rotating propellers whereby the efliciency of the power plant will be materially increased.

Another very important object of the invention is' to provide an airplane propulsion means of the aforementioned character comprising a yieldable thrust bearing whereby longitudinal movement of one of the propellers toward and away from the other will be permitted.

Other objects of the invention are to provide an airplane propulsion means of the character described which will be comparatively simple in construction, strong, durable, compact, light in weight and which may be manufactured at low cost. a

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specification, taken in connection with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure 1 is a view in vertical longitudinal section through an embodiment of the invention.

Figure 2 is a view in cross section therethrough.

Figure 3 is a detail view in cross section, taken substantially on the line 3-3 of Fig. 1.

Figure 4 is a cross sectional view, taken substantially on the line 4-4 of Fig. 1.

Figure 5 is a detail view in perspective of on of the thrust bearing adjusting screws.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a housing of suitable metal which is designated generally by the reference numeral I, said housing being of substantially the longitudinal shape shown to advantage in Fig. l of the drawings. The housing I is for the reception of asuitable lubricant and said housing includes .complemental half sections 2 and 3 which are bolted together, as at 4 (see Fig. 2).

Journaled in the housing I and extending longitudinally therethrough is a shaft 5 which is driven by the engine (not shown) of the airplane. Fixed on the forward end portion of the shaft 5 is a, propeller 5. The reference numeral 1 designates a gear which is fixed on the shaft 5 in the rear portion of the housing I. A vertical supporting bar 8 is provided at an inter- 6 mediate point in the housing I through which the shaft 5 extends. Suitable bearings 9 are provided in the housing I for the shaft 5. The reference numeral l0 designates countershafts which are journaled in the housing I. Fixed on the rear portions of the countershafts ID are gears II which are driven by the gear I. Fixed on the forward portions of the countershafts III are comparatively small gears I2.

The reference numeral I3 designates comparatively short countershafts which are journaled 10 in the'forward portion of the housing I between the shaft 5, and countershafts I 0. Reversing gears I4 are mounted on the countershafts I3. Gears I4 are driven by the gears I2.

' Journaled in the forward portion of the hous 15 ing I and rotatably and slidably mounted on the shaft 5 is a tubular shaft I5. Fixed on the forward end portion of the shaft I5 is a propeller I6. Fixed on, the rear portion of the tubular shaft I5 is a comparatively long gear I! which is driven by the gears I4.

The tubular shaft I5 is rotatably and slidably mounted in a combination radial and thrust bearing I8 which is provided therefor in the forward portion of the housing I. Antifriction balls 5 I9 are interposed between the bearing I8 and gear II. Forward sliding movement of the bearing I8 is yieldingly resisted by coil springs 20 .i which are mounted in a chamber 2| provided therefor in the forward portion of the housing I. One end of the coil springs 2!! is engaged with adjusting screws 22 which are threadedly mounted in the forward portion of the housing I and through the medium of which the tension of said coil springs may be regulated. It will 35 be noted that the headed ends of the screws 20 are located in the chamber 2| for engagement by the coil springs 20.

It is thought that the operation of the apparatus will be readily apparent from a consideration of the foregoing. The front propeller 6 on the shaft 5 is rotated in one direction by the engine. Through the gears I, II, I2, I4 and H the propeller I6 on the tubular shaft I5 is driven in the opposite direction at the same speed. The 45 coil springs 20 of the bearing I8 permit longitudinal movement of the propeller I6 toward and away from the front propeller 6. Of course, during this longitudinal movement of the propeller It the comparatively long gear I! remains 50 in mesh with the gears I4.

It is believed that the many advantages of an airplane propulsion means constructed in accordance with the present invention will be readily understood and although a preferred embodi- 66 ment of the apparatus is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted 5 to which will fall within the scope of the invention as claimed.

What is claimed is: An airplane propulsion means comprising a housing, a shaft extending rotatably through 10 said housing, a propeller fixed on said shaft, a

tubular shaft rotatably and slidably mounted on the first named shaft, a propeller fixed on said tubular shaft, means including a gear on the tubular shaft 'operatively connecting the tubu- 

